I think the title sums it up but since every single thing in the universe can be referred to as a noun and German assigns every noun a gender who gets to decide the gender?

Furthermore, other European languages have similar issues other than English. Is there some sort of agreement on gender? If something is female in German does it tend to be female in other European languages?

Going forward all new nouns such as I just bought a new 'iPhone' will be of neutral gender? A thousand years from now new things will be invented so it's not just an issue now but far into the future as well.

Well, perhaps it might be that gender in related languages is - based on historical reasons - often equally but in general: No, you can't conclude from one to another. There are some rule of thumbs when to use which gender (probably in all languages) and if you create a new word it likely will follow these rules, too. I am not sure, however, if there's any commission for deciding the gender. This question also seems to be a bit broader and would be of more interest on linguistics - including comparison of different languages, respectively their way to handle such a thing.
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Em1Nov 15 '12 at 18:14

2 Answers
2

There is no fixed "rule" to define the gender of a loanword in German. This means that we have to look them up in a dictionary when in doubt.

Still, some principles hold true for many loanwords that have been nicely summarized with some examples in the essay on the "Gender of foreign nouns" from canoo.net:

The "origin principle": Foreign nouns have the same gender as in the original language

Analogy with other words having the same ending

Analogy with the German translation

Analogy with other nouns belonging to the same semantic group

Some of these principles will also hold true for new words that are not loanwords. Dictionaries such as Duden will then over time list the variation used the most to make this the "valid" form that can be taught to children in school. Still sometimes more than one variation persist.